package com.uwo.tools.aibum.localphoto;

import android.app.Activity;
import android.content.Intent;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Matrix;
import android.graphics.PointF;
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.util.FloatMath;
import android.view.LayoutInflater;
import android.view.MotionEvent;
import android.view.View;
import android.view.View.OnClickListener;
import android.view.View.OnTouchListener;
import android.view.ViewGroup;
import android.widget.Button;
import android.widget.ImageView;
import android.widget.Toast;

import com.uwo.tools.aibum.R;

public class ImageMatrix extends Fragment {
    private ImageView ivShow;
    private Button btnChoose;
    private String path;

    @Override
    public void onActivityCreated(Bundle savedInstanceState) {
        super.onActivityCreated(savedInstanceState);
        ivShow = (ImageView) getView().findViewById(R.id.iv_show);
        ivShow.setOnTouchListener(new TouchListener());
        btnChoose = (Button) getView().findViewById(R.id.btn_choose);
        btnChoose.getBackground().setAlpha(80);
        Bundle args = getArguments();
        path = args.getString("path_absolute");
        Bitmap bm = BitmapFactory.decodeFile(path);
        ivShow.setImageBitmap(bm);
        btnChoose.setOnClickListener(new OnClickListener() {
            @Override
            public void onClick(View paramView) {
                Intent intent = new Intent();
                intent.putExtra("", path);
                getActivity().setResult(20, intent);//设置返回数据

                Toast.makeText(getActivity(), "已选择", Toast.LENGTH_SHORT).show();
            }
        });
    }

    @Override
    public void onAttach(Activity activity) {
        super.onAttach(activity);
    }

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
    }

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {
        return inflater.inflate(R.layout.imgmatrix, container, false);
    }

    class TouchListener implements OnTouchListener {
        private int mode = 0;        //记录是拖拉照片模式还是放大缩小照片模式
        private static final int MODE_DRAG = 1;        //拖拉照片模式
        private static final int MODE_ZOOM = 2;        //放大缩小照片模式

        private PointF startPointF = new PointF();    //用于记录开始时候的坐标位置

        private Matrix matrix = new Matrix();            //用于记录拖拉图片移动的坐标位置
        private Matrix currentMatrix = new Matrix();    //用于记录图片要进行拖拉时候的坐标位置

        private float startDis;                        //两个手指的开始距离
        private PointF midPointF;                    //两个手指的中间点

        @Override
        public boolean onTouch(View v, MotionEvent event) {
            /** 通过与运算保留最后八位 MotionEvent.ACTION_MASK = 255 */
            switch (event.getAction() & MotionEvent.ACTION_MASK) {
                // 手指压下屏幕  触发
                case MotionEvent.ACTION_DOWN:
                    mode = MODE_DRAG;
                    // 记录ImageView当前的移动位置
                    currentMatrix.set(ivShow.getImageMatrix());
                    startPointF.set(event.getX(), event.getY());
                    break;
                // 手指在屏幕上移动，改事件会被不断触发
                case MotionEvent.ACTION_MOVE:
                    if (mode == MODE_DRAG) {
                        float dx = event.getX() - startPointF.x;// 得到x轴的移动距离
                        float dy = event.getY() - startPointF.y;// 得到x轴的移动距离
                        // 在没有移动之前的位置上进行移动
                        matrix.set(currentMatrix);
                        matrix.postTranslate(dx, dy);
                    } else if (mode == MODE_ZOOM) {        // 放大缩小图片
                        float endDis = distance(event);// 结束距离
                        if (endDis > 10f) {        // 两个手指并拢在一起的时候像素大于10
                            float scale = endDis / startDis;    // 得到缩放倍数
                            matrix.set(currentMatrix);
                            matrix.postScale(scale, scale, midPointF.x, midPointF.y);
                        }
                    }
                    break;
                // 手指离开屏幕
                case MotionEvent.ACTION_UP:
                    // 当触点离开屏幕，但是屏幕上还有触点(手指)
                case MotionEvent.ACTION_POINTER_UP:
                    mode = 0;
                    break;
                // 当屏幕上已经有触点(手指)，再有一个触点压下屏幕
                case MotionEvent.ACTION_POINTER_DOWN:
                    mode = MODE_ZOOM;
                    /** 计算两个手指间的距离 */
                    startDis = distance(event);
                    /** 计算两个手指间的中间点 */
                    if (startDis > 10f) {// 两个手指并拢在一起的时候像素大于10
                        midPointF = mid(event);
                        //记录当前ImageView的缩放倍数
                        currentMatrix.set(ivShow.getImageMatrix());
                    }
                    break;
            }
            ivShow.setImageMatrix(matrix);
            return true;
        }

        private float distance(MotionEvent event) {
            float dx = event.getX(1) - event.getX(0);
            float dy = event.getY(1) - event.getY(0);
            /** 使用勾股定理返回两点之间的距离 */
            return (float) Math.sqrt(dx * dx + dy * dy);
//            return FloatMath.sqrt(dx * dx + dy * dy);
        }

        /**
         * 计算两个手指间的中间点
         */
        private PointF mid(MotionEvent event) {
            float midX = (event.getX(1) + event.getX(0)) / 2;
            float midY = (event.getY(1) + event.getY(0)) / 2;
            return new PointF(midX, midY);
        }
    }
}
